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-rw-r--r--java.html.markdown63
1 files changed, 63 insertions, 0 deletions
diff --git a/java.html.markdown b/java.html.markdown
index 35ec57d8..bc119eb1 100644
--- a/java.html.markdown
+++ b/java.html.markdown
@@ -7,6 +7,7 @@ contributors:
- ["Simon Morgan", "http://sjm.io/"]
- ["Zachary Ferguson", "http://github.com/zfergus2"]
- ["Cameron Schermerhorn", "http://github.com/cschermerhorn"]
+ - ["Raphael Nascimento", "http://github.com/raphaelbn"]
filename: LearnJava.java
---
@@ -670,6 +671,68 @@ public abstract class Mammal()
return true;
}
}
+
+
+// Enum Type
+//
+// An enum type is a special data type that enables for a variable to be a set of predefined constants. The // variable must be equal to one of the values that have been predefined for it.
+// Because they are constants, the names of an enum type's fields are in uppercase letters.
+// In the Java programming language, you define an enum type by using the enum keyword. For example, you would
+// specify a days-of-the-week enum type as:
+
+public enum Day {
+ SUNDAY, MONDAY, TUESDAY, WEDNESDAY,
+ THURSDAY, FRIDAY, SATURDAY
+}
+
+// We can use our enum Day like that:
+
+public class EnumTest {
+
+ // Variable Enum
+ Day day;
+
+ public EnumTest(Day day) {
+ this.day = day;
+ }
+
+ public void tellItLikeItIs() {
+ switch (day) {
+ case MONDAY:
+ System.out.println("Mondays are bad.");
+ break;
+
+ case FRIDAY:
+ System.out.println("Fridays are better.");
+ break;
+
+ case SATURDAY:
+ case SUNDAY:
+ System.out.println("Weekends are best.");
+ break;
+
+ default:
+ System.out.println("Midweek days are so-so.");
+ break;
+ }
+ }
+
+ public static void main(String[] args) {
+ EnumTest firstDay = new EnumTest(Day.MONDAY);
+ firstDay.tellItLikeItIs();
+ EnumTest thirdDay = new EnumTest(Day.WEDNESDAY);
+ thirdDay.tellItLikeItIs();
+ }
+}
+
+// The output is:
+// Mondays are bad.
+// Midweek days are so-so.
+
+// Enum types are much more powerful than we show above.
+// The enum body can include methods and other fields.
+// You can se more at https://docs.oracle.com/javase/tutorial/java/javaOO/enum.html
+
```
## Further Reading